A typical vapor compression refrigeration system includes a compressor, a condenser, an evaporator and expansion device arranged to transfer heat energy between a refrigerant in heat transfer relationship with air in the evaporator and in the condenser.
The evaporator removes or extracts unwanted heat, cooling air which is forced across the evaporation coils. The purpose of the condenser is to extract heat from the refrigerant transferring heat to the outside air. Within the refrigeration system, the expansion device is located in the refrigerant line ahead of the evaporator. High pressure liquid reaches the expansion device and the pressure of the refrigerant is reduced as it passes through the expansion device. In many systems, the evaporator has a plurality of circuits or conduits which carry the refrigerant and a fan or blower forces air across the multiple circuits in heat exchange relationship to cool the air. Various heat exchanger designs are available such as flat plate, fin and tube and others which are intended to increase the heat exchange efficiency between the refrigerant and the airflow.
Refrigeration systems of the type are widely used in various applications such as ice machines, automotive air conditioners, residential and commercial air conditioners, appliances and refrigeration systems for walk-in coolers. Some systems of this type may be reversible or designed at heat pump systems, often used for residential heating and cooling.
Various types of expansion devices can be found in the prior art. My prior patent, U.S. Pat. No. 6,672,091 discloses an expansion device for a refrigeration system having a piston which reciprocates to either open or close ports to increase or decrease the volume of atomizer refrigerant liquid received from the condenser. Atomization may be enhanced by using an auxiliary, ultrasonic electrostatic devices.